The invention relates to an image camera comprising an image sensor for generating image signals representative of images picked up by said image sensor; a signal processor for processing said image signal to obtain an adjusted video signal in accordance with adjustment parameters, and means for generating said adjustment parameters. The invention also relates to a method of adjusting such a television camera.
Image cameras as defined in the opening paragraph are generally known. An example of a commercially available professional television camera is the LDK100 of Philips Digital Video Systems.
Television cameras, both professional and consumer cameras, require a number of parameters to be controlled. Parameters such as zoom, focus, iris, etc. relate to the optical path of the camera. Parameters such as white balance, gamma, contour, etc. relate to the electrical video processing. Some parameters are continuously controlled during operation. Other parameters need to be adjusted once in a set-up procedure before the camera is put into operation. The latter adjustments may require a specific test image. For example, white balance is adjusted using a white test card, and contour is adjusted using a frequency pattern card. Other adjustments require a real image. For example, a skin detection circuit in the camera is to be adjusted in such a way that a person""s skin colour is distinctly different from other colours in the scene. The adjustment parameters are then fixedly stored until external conditions change. The set-up procedure requires the controlling person to see the results of his adjustments in the viewfinder or on a monitor.
A drawback of the known set-up procedure is that the person acting before the camera has to stand still for a while. Further, there is a tendency in electronic news gathering to make a single person responsible for both recording the scene and acting in the scene (for example, conducting an interview). In such operation conditions, the set-up procedure requires the video reporter himself to act in the scene before the camera lens and simultaneously adjust the camera. Needless to say that this poses a problem.
It is an object of the invention to provide an improved image camera which alleviates the above-mentioned drawback.
To this end, the image camera in accordance with the invention comprises a memory circuit connected between said image sensor and said signal processor, which memory circuit is arranged to store the image signal in response to a first user-operable control command and repeatedly apply the stored image signal to the signal processor until receipt of a second user-operable control command.
The invention provides the possibility of xe2x80x9cfreezingxe2x80x9d the image (or even a sequence of images if the memory has a large capacity) as picked-up by the image sensor. The camera can then be adjusted on the basis of the frozen image. For example, the video reporter may freeze an image of himself and then adjust the skin detection circuit while observing the result in the viewfinder.
In an embodiment of the invention, the camera comprises a remote control receiver arranged to receive at least the first user-operable command from a remote control transmitter.
Advantageously, the memory is further arranged to also perform other functions such as scan format conversion and frame rate conversion.